Significance of property mismatch in the patch repair of structural concrete Part 2: Axially loaded reinforced concrete members

1990 ◽  
Vol 42 (152) ◽  
pp. 161-170 ◽  
Author(s):  
N. K. Emberson ◽  
G. C. Mays
Keyword(s):  
Reinforced Concrete ◽  
Patch Repair ◽  
Structural Concrete ◽  
Concrete Members ◽  
Concrete Part ◽  
Axially Loaded

FLEXURAL DUCTILITY OF STRUCTURAL CONCRETE MEMBERS SUBJECTED TO LIMITED CYCLES OF REPEATED LOADING

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Nazar Oukaili ◽  
Mohammed Khattab
Keyword(s):  
Reinforced Concrete ◽  
Prestressed Concrete ◽  
Concrete Beams ◽  
Constant Load ◽  
Reinforced Concrete Beams ◽  
Repeated Loading ◽  
Structural Concrete ◽  
Concrete Members ◽  
Flexural Ductility ◽  
High Level

For structural concrete members that may expose to serious earthquake, overload or accident impact, the design of ductility must be given the same importance as the flexural strength. The aim of this investigation is to study the change in ductility of structural concrete flexural members during their exposure to limited cycles of repeated loading. Twenty full-scale beam specimens have been fabricated in to two identical groups; each group consisted of ten specimens. The first group was tested under monotonic static loading to failure and regarded as control beams, while the specimens of the second group were subjected to ten cycles of repeated loading with constant load interval, which ranged between 40% and 60% of ultimate load. Specimens in each group were categorized as follows: two traditional reinforced concrete specimens with different intensity of tension reinforcement; three partially prestressed specimens with bonded strands; three partially prestressed specimens with unbonded strands; and two fully prestressed concrete specimens. The main variable, which was considered for all specimens was the partial prestressing ratio (PPR). It was observed that, the ductility of reinforced concrete beams was insignificantly increased during subjecting to limited repeated loading. For fully prestressed and partially prestressed concrete beams with high level of PPR, the ductility was significantly enhanced, while, it was decreased for specimens with small level of PPR.

scholarly journals Performance of Cement-Based Patch Repair Materials in Plain and Reinforced Concrete Members

2016 ◽  
Vol 13 (2) ◽  
pp. 160
Author(s):  
A.H. Al-Saidy
Keyword(s):  
Mechanical Properties ◽  
Reinforced Concrete ◽  
Concrete Beams ◽  
Plain Concrete ◽  
Reinforced Concrete Beams ◽  
Patch Repair ◽  
Concrete Members ◽  
Repair Materials ◽  
Superior Mechanical Properties ◽  
The Cost

Structural elements such as beams, slabs, and columns may require strengthening or repair during their service life. Different repair materials (RMs) are available and it is usually difficult to choose the best ones, especially when considering the cost of such materials. This paper presents the results of an experimental investigation of patch RMs on plain concrete prisms as well as on reinforced concrete beams. Three cement-based RMs available in the market with different mechanical properties and an ordinary Portland cement (OPC) mix produced in the lab were used in the study. Damage was induced in prisms/beams and then repaired using different materials. The experimental work included assessment of the flexural strength of damaged/repaired plain concrete prisms; slant shear (bond) strength between the concrete and the RM; axial strength of damaged/repaired plain concrete prisms and bond of the repair materials in damaged/repaired reinforced concrete beams loaded to failure. The test results showed that all RMs performed well in restoring the strength of damaged plain concrete. Compatibility of the RMs with substrate concrete was found to be more important in the behavior than superior mechanical properties of the RMs. No difference was noted in the behavior between the RMs in repairing reinforced concrete beams at the tension side. 

scholarly journals Application of Sustainable Bamboo-Based Composite Reinforcement in Structural-Concrete Beams: Design and Evaluation

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 696 ◽  
Author(s):  
Alireza Javadian ◽  
Ian F. C. Smith ◽  
Dirk E. Hebel
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Design Guidelines ◽  
Reinforced Concrete Beams ◽  
Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Structural Concrete ◽  
Concrete Members ◽  
Reinforced Polymer ◽  
Composite Reinforcement

Reinforced concrete is the most widely used building material in history. However, alternative natural and synthetic materials are being investigated for reinforcing concrete structures, given the limited availability of steel in developing countries, the rising costs of steel as the main reinforcement material, the amount of energy required by the production of steel, and the sensitivity of steel to corrosion. This paper reports on a unique use of bamboo as a sustainable alternative to synthetic fibers for production of bamboo fiber-reinforced polymer composite as reinforcement for structural-concrete beams. The aim of this study is to evaluate the feasibility of using this novel bamboo composite reinforcement system for reinforced structural-concrete beams. The bond strength with concrete matrix, as well as durability properties, including the water absorption and alkali resistance of the bamboo composite reinforcement, are also investigated in this study. The results of this study indicate that bamboo composite reinforced concrete beams show comparable ultimate loads with regards to fiber reinforced polymer (FRP) reinforced concrete beams according to the ACI standard. Furthermore, the results demonstrate the potential of the newly developed bamboo composite material for use as a new type of element for non-deflection-critical applications of reinforced structural-concrete members. The design guidelines that are stated in ACI 440.1R-15 for fiber reinforced polymer (FRP) reinforcement bars are also compared with the experimental results that were obtained in this study. The American Concrete Institute (ACI) design guidelines are suitable for non-deflection-critical design and construction of bamboo-composite reinforced-concrete members. This study demonstrates that there is significant potential for practical implementation of the bamboo-composite reinforcement described in this paper. The results of this study can be utilized for construction of low-cost and low-rise housing units where the need for ductility is low and where secondary-element failure provides adequate warning of collapse.

Behaviour of patch repair of axially loaded reinforced concrete beams

2006 ◽  
Vol 28 (8) ◽  
pp. 734-741 ◽  
Author(s):  
Alfarabi Sharif ◽  
Muhammad Kalimur Rahman ◽  
Ahmad S. Al-Gahtani ◽  
Mohammed Hameeduddin
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Patch Repair ◽  
Axially Loaded

scholarly journals Exploitation of Ultrahigh-Performance Fibre-Reinforced Concrete for the Strengthening of Concrete Structural Members

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Mohammed A. Al-Osta
Keyword(s):  
Reinforced Concrete ◽  
Environmental Conditions ◽  
Design Guidelines ◽  
Fibre Reinforced Concrete ◽  
Structural Members ◽  
Structural Concrete ◽  
Concrete Members ◽  
Service Load ◽  
Durability Performance ◽  
Load Conditions

The repair and strengthening of reinforced concrete members are very important due to several factors, including unexpected increases in load levels and/or the damaging impact of aggressive environmental conditions on structural concrete members. Many researchers have turned to using materials for the repair and strengthening of damaged structures or the construction of new concrete structural members. Ultrahigh-performance fibre-reinforced concrete (UHPFRC), characterized by superior structural and durability performance in aggressive environmental conditions, is one of the materials that have been considered for the repair and strengthening of concrete structural members. The repair or strengthening of concrete structures using UHPFRC needs a thorough knowledge of the behaviour of both the strengthening material and the strengthened concrete structure at service load conditions, in addition to an understanding of the design guidelines governing the use of such materials for effective repair and strengthening. In this study, the recent issues and findings regarding the use of UHPFRC as a repair or strengthening material for concrete structural members are reviewed, analysed, and discussed. In addition, recommendations were made concerning areas where future attention and research on the use of UHPFRC as a strengthening material needs to be focused if the material is to be applied in practice.

scholarly journals STRENGTH ANALYSIS OF AN OBLIQUE SECTION ACCORDING TO ELASTIC-PLASTIC CHARACTERISTICS/ĮSTRIŽO PJŪVIO STIPRUMO APSKAIČIAVIMAS ĮVERTINANT TAMPRIĄSIAS IR PLASTINES MEDŽIAGOS DEFORMACIJAS

1999 ◽  
Vol 5 (3) ◽  
pp. 200-205
Author(s):  
Vytautas A. Svetlauskas
Keyword(s):  
Reinforced Concrete ◽  
Structural Analysis ◽  
Strength Analysis ◽  
Equilibrium Equations ◽  
Shear Forces ◽  
Pure Bending ◽  
Oblique Section ◽  
Concrete Members ◽  
Concrete Layer ◽  
Concrete Part

The equilibrium of a reinforced concrete members part limited by one oblique and two vertical sections and exposed to shear forces is under consideration. Three equilibrium equations system of the forces of this reinforced concrete part and the condition of its failure are given. The assumptions and the possibility of solution of this system are considered. The analysis of the values of oblique section forces is presented. The position of a permanent dangerous oblique section and the height of compression concrete layer on its peak, ie the position of weakest design oblique section, is discussed. The bearing capacity of an oblique section is analysed. The recommendations presented are universal. If oblique forces can be neglected, the formulae can be used for structural analysis of normal section in a pure bending zone.

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